Semiconductor device

ABSTRACT

A semiconductor device includes a semiconductor element, a first lead including a mounting portion for the semiconductor element and a first terminal portion connected to the mounting portion, and a sealing resin covering the semiconductor element and a portion of the first lead. The mounting portion has a mounting-portion front surface and a mounting-portion back surface opposite to each other in a thickness direction, with the semiconductor element mounted on the mounting-portion front surface. The sealing resin includes a resin front surface, a resin back surface and a resin side surface connecting the resin front surface and the resin back surface. The mounting-portion back surface of the first lead is flush with the resin back surface. The first terminal portion includes a first-terminal-portion back surface exposed from the resin back surface, in a manner such that the first-terminal-portion back surface extends to the resin side surface.

FIELD

The present disclosure relates to semiconductor devices.

BACKGROUND

Semiconductor devices incorporating active elements (such astransistors) are available in various configurations. JP-A-2013-69720,for example, discloses a conventional semiconductor device whichincludes a semiconductor element, a die pad, a plurality of leads and asealing resin. The semiconductor element is attached to the die pad andelectrically connected to the leads. The sealing resin covers thesemiconductor element and the leads in a predetermined manner. Thebottom surface of the die pad is exposed from the sealing resin to beused as a terminal or heat-dissipating area that will be bonded to acorresponding part of e.g., a circuit board when the semiconductordevice is mounted on the board.

Due to the above configuration of the conventional semiconductor device,one cannot see the bonding portion between the terminal (orheat-dissipating outlet) and the circuit board once the semiconductordevice has been mounted on the circuit board. Unfavorably, suchconcealment of the bonding portion hinders visual checking of thebonding state between the terminal and the circuit board, which isdisadvantageous to achieving efficient inspection of the soundness ofthe bonding portion.

SUMMARY

In light of the above circumstances, the present disclosure aims toprovide a semiconductor device with which the soundness of the bondingbetween the semiconductor device (in particular, a lead carrying asemiconductor element) and an external support member (such as a circuitboard) can be confirmed simply by inspecting the appearance of theassembly of the semiconductor device and the support member.

According to an aspect of the present disclosure, there is provided asemiconductor device including: a semiconductor element; a first leadthat includes a mounting portion on which the semiconductor element ismounted, and a first terminal portion connected to the mounting portion;and a sealing resin covering the semiconductor element and a portion ofthe first lead. The mounting portion includes a mounting-portion frontsurface and a mounting-portion back surface that are opposite to eachother in a thickness direction, with the semiconductor element beingmounted on the mounting-portion front surface. The sealing resinincludes a resin front surface, a resin back surface and a resin sidesurface, where the resin front surface and the resin back surface areopposite to each other in the thickness direction, and the resin sidesurface connects the resin front surface and the resin back surface. Themounting-portion back surface is flush with the resin back surface. Thefirst terminal portion includes a first-terminal-portion back surfaceexposed from the resin back surface. The first-terminal-portion backsurface extends to the resin side surface.

Other features and advantages of the present disclosure will be moreapparent from the detailed description given below with reference to theaccompanying drawings.

DRAWINGS

FIG. 1 is a perspective view of a semiconductor device according to afirst embodiment.

FIG. 2 is a plan view of the semiconductor device shown in FIG. 1 .

FIG. 3 is a front view of the semiconductor device shown in FIG. 1 .

FIG. 4 is a bottom view of the semiconductor device shown in FIG. 1 .

FIG. 5 is a right side view of the semiconductor device shown in FIG. 1.

FIG. 6 is a sectional view taken along line VI-VI of FIG. 2 .

FIG. 7 is a sectional view taken along line VII-VII of FIG. 2 .

FIG. 8 is a plan view illustrating a manufacturing step of thesemiconductor device shown in FIG. 1 .

FIG. 9 is a plan view illustrating a manufacturing step of thesemiconductor device shown in FIG. 1 .

FIG. 10 is a perspective view of the semiconductor device of FIG. 1mounted on a circuit board.

FIG. 11 is a perspective view of a semiconductor device according to asecond embodiment.

FIG. 12 is a right side view of the semiconductor device shown in FIG.11 .

FIG. 13 is a bottom view of a semiconductor device according to a thirdembodiment.

FIG. 14 is a bottom view of a semiconductor device according to a fourthembodiment.

FIG. 15 is a bottom view of a semiconductor device according to a fifthembodiment.

FIG. 16 is a bottom view of a semiconductor device according to a sixthembodiment.

FIG. 17 is a bottom view of a semiconductor device according to aseventh embodiment.

FIG. 18 is a perspective view of a semiconductor device according to aneighth embodiment.

EMBODIMENTS

The following describes embodiments of semiconductor device inaccordance with the present disclosure with reference to theaccompanying drawings.

With reference to FIGS. 1 to 7 , a semiconductor device A1 according toa first embodiment will be described. The semiconductor device A1includes a plurality of leads 1 to 5, a semiconductor element(s) 6,bonding wires 71 and 72, and a sealing resin 8. In the illustratedexample, as described in detail below, the semiconductor device A1includes two semiconductor elements 6 a, 6 b.

FIG. 1 is a perspective view of the semiconductor device A1. FIG. 2 is aplan view of the semiconductor device A1. In FIG. 2 , the sealing resin8 is shown in phantom lines (chain double-dashed line) representing thecontour of the sealing resin 8. FIG. 3 is a front view of thesemiconductor device A1. FIG. 4 is a bottom view of the semiconductordevice A1. FIG. 5 is a right side view of the semiconductor device A1.FIG. 6 is a sectional view taken along line VI-VI of FIG. 2 . FIG. 7 isa sectional view taken along line VII-VII of FIG. 2 .

The semiconductor device A1 is for surface mounting on a circuit board,for example. The semiconductor device A1 is rectangular as viewed in thethickness direction (as seen in plan view). For purpose of description,the thickness direction of the semiconductor device A1 is defined as zdirection. A direction perpendicular to the z direction and parallel toan edge of the semiconductor device A1 (the horizontal direction in FIG.2 ) is defined as x direction. The direction perpendicular to the z andx directions (the vertical direction in FIG. 2 ) is defined as ydirection. The size of the semiconductor device A1 is not specificallylimited. In the present embodiment, the semiconductor device A1 is about1 to 10 mm in the x direction, 1 to 10 mm in the y direction, and 0.3 to3 mm in the z direction.

The leads 1 to 5 may support the semiconductor element 6 (6 a and 6 b)or may be electrically connected to the semiconductor element 6 (6 a or6 b). The leads 1 to 5 are formed from a metal plate processed bypunching or bending, for example. The leads 1 to 5 are made of a metal,which is preferably Cu, Ni, an alloy of Cu and Ni, or Alloy 42. In thepresent embodiment, the leads 1 to 5 are made of Cu. The thickness ofthe leads 1 to 5 may be from 0.08 to 0.5 min, and in the presentembodiment, it is about 0.125 mm. In the following description, theleads 1 to 5 may be referred to individually as a first lead 1, a secondlead 2, a third lead 3, a fourth lead 4 and a fifth lead 5.

As shown in FIG. 2 , the first lead 1 is located at the center thesemiconductor device A1 in the y direction and extends from one side tothe other in the x direction. The second lead 2 and the third lead 3 areat the opposite sides of the first lead 1 in the y direction and spacedapart from the first lead 1. The fourth lead 4 and the fifth lead 5 areat the opposite sides of the first lead 1 in the y direction and spacedapart from the first lead 1. The second lead 2 and the fourth lead 4 areat the same side of the first lead 1 in the y direction (the lower sidein FIG. 2 ) and spaced apart from each other in the x direction. Thethird lead 3 and the fifth lead 5 are located at the same side of thefirst lead 1 in the y direction (the upper side in FIG. 2 ) and spacedapart from each other in the x direction. As viewed in the z direction,the first lead 1 is the largest, and the fourth lead 4 and the fifthlead 5 are the smallest.

The first lead 1 includes a mounting portion 110, first-lead terminalportions 120 and a first-lead connecting portion 130.

The mounting portion 110 is generally rectangular and located at thecenter of the first lead 1 as viewed in the z direction. The mountingportion 110 has a mounting-portion front surface 111 and amounting-portion back surface 112. The mounting-portion front surface111 and the mounting-portion back surface 112 face opposite to eachother in the z direction. The mounting-portion front surface 111 facesupward in FIGS. 3 and 5 . The mounting-portion front surface 111 iswhere the semiconductor element 6 is mounted. The mounting-portion backsurface 112 faces downward in FIGS. 3 and 5 . The mounting-portion backsurface 112 is exposed from the sealing resin 8 and serves as a backsurface terminal.

Each first-lead terminal portion 120 is connected to the mountingportion 110 and rectangular as viewed in the z direction. In thisembodiment, two first-lead terminal portions 120 are provided on eitherend face of the mounting portion 110 in the x direction, such that eachfirst-lead terminal portion 120 is located between an end and the centerin the y direction. That is, a total of four first-lead terminalportions 120 are provided. Each first-lead terminal portion 120 has afirst-lead-terminal-portion front surface 121, afirst-lead-terminal-portion back surface 122 and afirst-lead-terminal-portion end face 123. Thefirst-lead-terminal-portion front surface 121 and thefirst-lead-terminal-portion back surface 122 face opposite to each otherin the z direction. The first-lead-terminal-portion front surface 121faces upward in FIGS. 3 and 5 . The first-lead-terminal-portion frontsurface 121 is flush with the mounting-portion front surface 111. Thefirst-lead-terminal-portion back surface 122 faces downward in FIGS. 3and 5 . The first-lead-terminal-portion back surface 122 is flush withthe mounting-portion back surface 112. The first-lead-terminal-portionend face 123 is a surface facing outward in the x direction andconnecting the first-lead-terminal-portion front surface 121 and thefirst-lead-terminal-portion back surface 122. Thefirst-lead-terminal-portion back surface 122 and thefirst-lead-terminal-portion end face 123 are exposed from the sealingresin 8 and connected to form a terminal (see FIG. 6 ).

The first-lead connecting portion 130 is connected to the mountingportion 110 so as to surround the mounting portion 110 as viewed in thez direction. The first-lead connecting portion 130 has a thickness(i.e., the dimension in the z direction) that is about half thethickness of the mounting portion 110. The first-lead connecting portion130 is formed by, for example, half etching. The first-lead connectingportion 130 has a first-lead-connecting-portion front surface 131, afirst-lead-connecting-portion back surface 132 andfirst-lead-connecting-portion end faces 133. Thefirst-lead-connecting-portion front surface 131 and thefirst-lead-connecting-portion back surface 132 face opposite to eachother in the z direction. The first-lead-connecting-portion frontsurface 131 faces upward in FIGS. 3 and 5 . Thefirst-lead-connecting-portion front surface 131 is flush with themounting-portion front surface 111. That is, the mounting-portion frontsurface 111, the first-lead-terminal-portion front surface 121 and thefirst-lead-connecting-portion front surface 131 form one planar surface(see FIG. 2 ). The first-lead-connecting-portion back surface 132 facesdownward in FIGS. 3 and 5 . The first-lead connecting portion 130 hasfour projections projecting outward in the x direction. As viewed in thez direction, two projections are provided on either side surface of thefirst-lead connecting portion 130 facing outward in the x direction,such that each projection is located between an end in the y directionand the first-lead terminal portion 120 nearest to the end. Eachfirst-lead-connecting-portion end face 133 is the end face of aprojection facing in the x direction and connecting thefirst-lead-connecting-portion front surface 131 and thefirst-lead-connecting-portion back surface 132. Thefirst-lead-connecting-portion end faces 133 are exposed from the sealingresin 8.

The first lead 1 has a surface plating layer (not shown) on all thesurfaces exposed from the sealing resin 8. In the present embodiment,the surface plating layer is provided on the mounting-portion backsurface 112, the first-lead-terminal-portion back surfaces 122, thefirst-lead-terminal-portion end faces 123 and thefirst-lead-connecting-portion end faces 133. The surface plating layeris made of a material having better solder wettability than the basematerial of the first lead 1. In the present embodiment, the surfaceplating layer is made of Au, for example. The surface plating layer isdeposited by electroless displacement plating in a manufacturing method,which will be described later.

The second lead 2 is located at a corner (lower right in FIG. 2 ) of thesemiconductor device A1 as viewed in the z direction and includes a wirebonding portion 210, three second-lead terminal portions 220 and asecond-lead connecting portion 230.

As viewed in the z direction, the wire bonding portion 210 is locatedgenerally at the center of the second lead 2 in the y direction and hasa rectangle shape that is long in the x direction. The wire bondingportion 210 has a wire-bonding-portion front surface 211 and awire-bonding-portion back surface 212. The wire-bonding-portion frontsurface 211 and the wire-bonding-portion back surface 212 face oppositeto each other in the z direction. The wire-bonding-portion front surface211 faces upward in FIGS. 3 and 5 . The wire-bonding-portion frontsurface 211 is where bonding wires 72 are bonded. Thewire-bonding-portion back surface 212 faces downward in FIGS. 3 and 5 .

Each second-lead terminal portion 220 is connected to the wire bondingportion 210 and rectangular as viewed in the z direction. The threesecond-lead terminal portions 220 are arranged side by side on one ofthe end faces of the wire bonding portion 210 in the y direction (theend face facing outside of the semiconductor device A1). Eachsecond-lead terminal portion 220 has a second-lead-terminal-portionfront surface 221, a second-lead-terminal-portion back surface 222 and asecond-lead-terminal-portion end face 223. Thesecond-lead-terminal-portion front surface 221 and thesecond-lead-terminal-portion back surface 222 face opposite to eachother in the z direction. The second-lead-terminal-portion front surface221 faces upward in FIGS. 3 and 5 . The second-lead-terminal-portionfront surface 221 is flush with the wire-bonding-portion front surface211. The second-lead-terminal-portion back surface 222 faces downward inFIGS. 3 and 5 . The second-lead-terminal-portion back surface 222 isflush with the wire-bonding-portion back surface 212. Thesecond-lead-terminal-portion end face 223 is a surface facing outward inthe y direction and connecting the second-lead-terminal-portion frontsurface 221 and the second-lead-terminal-portion back surface 222. Thewire-bonding-portion back surface 212, the second-lead-terminal-portionback surfaces 222 and the second-lead-terminal-portion end faces 223 areexposed from the sealing resin 8 and connected to form a terminal.

The second-lead connecting portion 230 is connected to the wire bondingportion 210 so as to surround the wire bonding portion 210 as viewed inthe z direction. The second-lead connecting portion 230 has a thickness(i.e., the dimension in the z direction) that is about half thethickness of the wire bonding portion 210. The second-lead connectingportion 230 is formed by, for example, half etching. The second-leadconnecting portion 230 has a second-lead-connecting-portion frontsurface 231, a second-lead-connecting-portion back surface 232 and asecond-lead-connecting-portion end face 233. Thesecond-lead-connecting-portion front surface 231 and thesecond-lead-connecting-portion back surface 232 face opposite to eachother in the z direction. The second-lead-connecting-portion frontsurface 231 faces upward in FIGS. 3 and 5 . Thesecond-lead-connecting-portion front surface 231 is flush with thewire-bonding-portion front surface 211. That is, thewire-bonding-portion front surface 211, the second-lead-terminal-portionfront surfaces 221 and the second-lead-connecting-portion front surface231 form one continuous planar surface (see FIG. 2 ). Thesecond-lead-connecting-portion back surface 232 faces downward in FIGS.3 and 5 . The second-lead connecting portion 230 has a projectionprojecting in the x direction (to the right in FIG. 2 ). Thesecond-lead-connecting-portion end face 233 is the end face of theprojection facing in the x direction and connecting thesecond-lead-connecting-portion front surface 231 and thesecond-lead-connecting-portion back surface 232. Thesecond-lead-connecting-portion end face 233 is exposed from the sealingresin 8.

The second lead 2 has a surface plating layer (not shown) on all thesurfaces exposed from the sealing resin 8. In the present embodiment,the surface plating layer is provided on the wire-bonding-portion backsurface 212, the second-lead-terminal-portion back surfaces 222, thesecond-lead-terminal-portion end faces 223 and thesecond-lead-connecting-portion end face 233. The surface plating layeris similar to the surface plating layer of the first lead 1 in that itis made of, for example, Au and deposited by electroless displacementplating.

The third lead 3 is located at a corner (upper right in FIG. 2 ) of thesemiconductor device A1 as viewed in the z direction and includes a wirebonding portion 310, three third-lead terminal portions 320 and athird-lead connecting portion 330.

As viewed in the z direction, the wire bonding portion 310 is locatedgenerally at the center of the third lead 3 and has a rectangle shapethat is long in the x direction. The wire bonding portion 310 has awire-bonding-portion front surface 311 and a wire-bonding-portion backsurface 312. The wire-bonding-portion front surface 311 and thewire-bonding-portion back surface 312 face opposite to each other in thez direction. The wire-bonding-portion front surface 311 faces upward inFIGS. 3 and 5 . The wire-bonding-portion front surface 311 is wherebonding wires 72 are bonded. The wire-bonding-portion back surface 312faces downward in FIGS. 3 and 5 .

Each third-lead terminal portion 320 is connected to the wire bondingportion 310 and rectangular as viewed in the z direction. The threethird-lead terminal portion 320 are arranged side by side on one of theend faces of the wire bonding portion 310 in the y direction (the endface facing outside of the semiconductor device A1). Each third-leadterminal portion 320 has a third-lead-terminal-portion front surface321, a third-lead-terminal-portion back surface 322 and athird-lead-terminal-portion end face 323. Thethird-lead-terminal-portion front surface 321 and thethird-lead-terminal-portion back surface 322 face opposite to each otherin the z direction. The third-lead-terminal-portion front surface 321faces upward in FIGS. 3 and 5 . The third-lead-terminal-portion frontsurface 321 is flush with the wire-bonding-portion front surface 311.The third-lead-terminal-portion back surface 322 faces downward in FIGS.3 and 5 . The third-lead-terminal-portion back surface 322 is flush withthe wire-bonding-portion back surface 312. Thethird-lead-terminal-portion end face 323 is a surface facing outward inthe y direction and connecting the third-lead-terminal-portion frontsurface 321 and the third-lead-terminal-portion back surface 322. Thewire-bonding-portion back surface 312, the third-lead-terminal-portionback surface 322 and the third-lead-terminal-portion end face 323 areexposed from the sealing resin 8 and connected to form a terminal.

The third-lead connecting portion 330 is connected to the wire bondingportion 310 so as to surround the wire bonding portion 310 as viewed inthe z direction. The third-lead connecting portion 330 has a thickness(i.e., the dimension in the z direction) that is about half thethickness of the wire bonding portion 310. The third-lead connectingportion 330 is formed by, for example, half etching. The third-leadconnecting portion 330 has a third-lead-connecting-portion front surface331, a third-lead-connecting-portion back surface 332 and athird-lead-connecting-portion end face 333. Thethird-lead-connecting-portion front surface 331 and thethird-lead-connecting-portion back surface 332 face opposite to eachother in the z direction. The third-lead-connecting-portion frontsurface 331 faces upward in FIGS. 3 and 5 . Thethird-lead-connecting-portion front surface 331 is flush with thewire-bonding-portion front surface 311. That is, thewire-bonding-portion front surface 311, the third-lead-terminal-portionfront surfaces 321 and the third-lead-connecting-portion front surface331 form one continuous planar surface (see FIG. 2 ). Thethird-lead-connecting-portion back surface 332 faces downward in FIGS. 3and 5 . The third-lead connecting portion 330 has a projectionprojecting in the x direction (to the right in FIG. 2 ). Thethird-lead-connecting-portion end face 333 is the end face of theprojection facing in the x direction and connecting thethird-lead-connecting-portion front surface 331 and thethird-lead-connecting-portion back surface 332. Thethird-lead-connecting-portion end face 333 is exposed from the sealingresin 8.

The third lead 3 has a surface plating layer (not shown) on all thesurfaces exposed from the sealing resin 8. In the present embodiment,the surface plating layer is provided on the wire-bonding-portion backsurface 312, the third-lead-terminal-portion back surfaces 322, thethird-lead-terminal-portion end faces 323 and thethird-lead-connecting-portion end face 333. The surface plating layer issimilar to the surface plating layer of the first lead 1 in that it ismade of, for example, Au and deposited by electroless displacementplating.

The fourth lead 4 is located at a corner (lower left in FIG. 2 ) of thesemiconductor device A1 as viewed in the z direction and includes afourth-lead terminal portion 420 and a fourth-lead connecting portion430.

The fourth-lead terminal portion 420 is rectangular as viewed in zdirection. The fourth-lead terminal portion 420 has afourth-lead-terminal-portion front surface 421, afourth-lead-terminal-portion back surface 422 and afourth-lead-terminal-portion end face 423. Thefourth-lead-terminal-portion front surface 421 and thefourth-lead-terminal-portion back surface 422 face opposite to eachother in the z direction. The fourth-lead-terminal-portion front surface421 faces upward in FIGS. 3 and 5 . The fourth-lead-terminal-portionfront surface 421 is where a bonding wire 71 is bonded. Thefourth-lead-terminal-portion back surface 422 faces downward in FIGS. 3and 5 . The fourth-lead-terminal-portion end face 423 is a surfacefacing outward in the y direction and connecting thefourth-lead-terminal-portion front surface 421 and thefourth-lead-terminal-portion back surface 422. Thefourth-lead-terminal-portion back surface 422 and thefourth-lead-terminal-portion end face 423 are exposed from the sealingresin 8 and connected to form a terminal.

The fourth-lead connecting portion 430 is connected to the fourth-leadterminal portion 420 so as to surround the fourth-lead terminal portion420 as viewed in the z direction. The fourth-lead connecting portion 430has a thickness (i.e., the dimension in the z direction) that is abouthalf the thickness of the fourth-lead terminal portion 420. Thefourth-lead connecting portion 430 is formed by, for example, halfetching. The fourth-lead connecting portion 430 has afourth-lead-connecting-portion front surface 431, afourth-lead-connecting-portion back surface 432 and afourth-lead-connecting-portion end face 433. Thefourth-lead-connecting-portion front surface 431 and thefourth-lead-connecting-portion back surface 432 face opposite to eachother in the z direction. The fourth-lead-connecting-portion frontsurface 431 faces upward in FIGS. 3 and 5 . Thefourth-lead-connecting-portion front surface 431 and thefourth-lead-terminal-portion front surface 421 form one continuousplanar surface (see FIG. 2 ). The fourth-lead-connecting-portion backsurface 432 faces downward in FIGS. 3 and 5 . The fourth-lead connectingportion 430 has a projection projecting in the x direction (to the leftin FIG. 2 ). The fourth-lead-connecting-portion end face 433 is the endface of the projection facing in the x direction and connecting thefourth-lead-connecting-portion front surface 431 and thefourth-lead-connecting-portion back surface 432. Thefourth-lead-connecting-portion end face 433 is exposed from the sealingresin 8.

The fourth lead 4 has a surface plating layer (not shown) on all thesurfaces exposed from the sealing resin 8. In the present embodiment, asurface plating is provided on the fourth-lead-terminal-portion backsurface 422, the fourth-lead-terminal-portion end face 423 and thefourth-lead-connecting-portion end face 433. The surface plating layeris similar to the surface plating layer of the first lead 1 in that itis made of, for example, Au and deposited by electroless displacementplating.

The fifth lead 5 is located at a corner (upper left in FIG. 2 ) of thesemiconductor device A1 as viewed in the z direction and includes afifth-lead terminal portion 520 and a fifth-lead connecting portion 530.

The fifth-lead terminal portion 520 is rectangular as viewed in zdirection. The fifth-lead terminal portion 520 has afifth-lead-terminal-portion front surface 521, afifth-lead-terminal-portion back surface 522 and afifth-lead-terminal-portion end face 523. Thefifth-lead-terminal-portion front surface 521 and thefifth-lead-terminal-portion back surface 522 face opposite to each otherin the z direction. The fifth-lead-terminal-portion front surface 521faces upward in FIGS. 3 and 5 . The fifth-lead-terminal-portion frontsurface 521 is where a bonding wire 71 is bonded. Thefifth-lead-terminal-portion back surface 522 faces downward in FIGS. 3and 5 . The fifth-lead-terminal-portion end face 523 is a surface facingoutward in the y direction and connecting thefifth-lead-terminal-portion front surface 521 and thefifth-lead-terminal-portion back surface 522. Thefifth-lead-terminal-portion back surface 522 and thefifth-lead-terminal-portion end face 523 are exposed from the sealingresin 8 and connected to form a terminal.

The fifth-lead connecting portion 530 is connected to the fifth-leadterminal portion 520 so as to surround the fifth-lead terminal portion520 as viewed in the z direction. The fifth-lead connecting portion 530has a thickness (i.e., the dimension in the z direction) that is abouthalf the thickness of the fifth-lead terminal portion 520. Thefifth-lead connecting portion 530 is formed by, for example, halfetching. The fifth-lead connecting portion 530 has afifth-lead-connecting-portion front surface 531, afifth-lead-connecting-portion back surface 532 and afifth-lead-connecting-portion end face 533. Thefifth-lead-connecting-portion front surface 531 and thefifth-lead-connecting-portion back surface 532 face opposite to eachother in the z direction. The fifth-lead-connecting-portion frontsurface 531 faces upward in FIGS. 3 and 5 . Thefifth-lead-connecting-portion front surface 531 and thefifth-lead-terminal-portion front surface 521 form one continuous planarsurface (see FIG. 2 ). The fifth-lead-connecting-portion back surface532 faces downward in FIGS. 3 and 5 . The fifth-lead connecting portion530 has a projection projecting in the x direction (to the left in FIG.2 ). The fifth-lead-connecting-portion end face 533 is the end face ofthe projection facing in the x direction and connecting thefifth-lead-connecting-portion front surface 531 and thefifth-lead-connecting-portion back surface 532. Thefifth-lead-connecting-portion end face 533 is exposed from the sealingresin 8.

The fifth lead 5 has a surface plating layer (not shown) on all thesurfaces exposed from the sealing resin 8. In the present embodiment, asurface plating layer is provided on the fifth-lead-terminal-portionback surface 522, the fifth-lead-terminal-portion end face 523 and thefifth-lead-connecting-portion end face 533. The surface plating layer issimilar to the surface plating layer of the first lead 1 in that it ismade of, for example, Au and deposited by electroless displacementplating.

The semiconductor element 6 is an element by which the electricalfunction of the semiconductor device A1 is achieved. The semiconductorelement 6 is not limited to any particular type. In the presentembodiment, the semiconductor element 6 is a transistor, such as ametal-oxide-semiconductor field-effect transistor (MOSFET). Thesemiconductor element 6 includes an element body 60, a first electrode61, a second electrode 62 and a third electrode 63.

The first electrode 61 and the second electrode 62 are disposed on thesurface of the element body 60 facing away from the first lead 1. Asshown in FIG. 5 , the third electrode 63 is disposed on the surface ofthe element body 60 facing the first lead 1. In the present embodiment,the first electrode 61 comprises a gate electrode, the second electrode62 comprises a source electrode, and the third electrode 63 comprises adrain electrode.

In the present embodiment, the semiconductor device A1 includes twosemiconductor elements 6. The two semiconductor elements 6 are locatednext to each other in the y direction on the first lead 1. In thefollowing description, the semiconductor element 6 located toward thesecond lead 2 and the fourth lead 4 is designated as a semiconductorelement 6 a, and the semiconductor element 6 located toward the thirdlead 3 and the fifth lead 5 is designated as a semiconductor element 6b. When it is not necessary to separately identify the semiconductorelements 6 a and 6 b, they may be collectively referred to as thesemiconductor elements 6.

The semiconductor element 6 a is attached to the mounting-portion frontsurface 111 of the first lead 1 with an electrically conductive bondingmaterial (not shown). Thus, the third electrode 63 of the semiconductorelement 6 a is electrically connected to the first lead 1 via thebonding material. A bonding wire 71 is connected to the first electrode61 of the semiconductor element 6 a and the fourth-lead-terminal-portionfront surface 421 of the fourth lead 4. Thus, the first electrode 61 ofthe semiconductor element 6 a is electrically connected to the fourthlead 4. A plurality of bonding wires 72 are connected to the secondelectrode 62 of the semiconductor element 6 a and thewire-bonding-portion front surface 211 of the second lead 2. Thus, thesecond electrode 62 of the semiconductor element 6 a is electricallyconnected to the second lead 2.

The semiconductor element 6 b is attached to the mounting-portion frontsurface 111 of the first lead 1 with an electrically conductive bondingmaterial (not shown). Thus, the third electrode 63 of the semiconductorelement 6 b is electrically connected to the first lead 1 via thebonding material. A bonding wire 71 is connected to the first electrode61 of the semiconductor element 6 b and the fifth-lead-terminal-portionfront surface 521 of the fifth lead 5. Thus, the first electrode 61 ofthe semiconductor element 6 b is electrically connected to the fifthlead 5. A plurality of bonding wires 72 are connected to the secondelectrode 62 of the semiconductor element 6 b and thewire-bonding-portion front surface 311 of the third lead 3. Thus, thesecond electrode 62 of the semiconductor element 6 b is electricallyconnected to the third lead 3.

Note that the semiconductor elements 6 and their connection to the leads1 to 5 described above are merely an example. The number, type andarrangement of the semiconductor elements 6 are not specificallylimited, and their wiring pattern is not limited either.

The sealing resin 8 covers the semiconductor elements 6 a and 6 b, thebonding wires 71 and 72, and a portion of each of the leads 1 to 5. Thesealing resin 8 may be made of a black epoxy resin, for example.

The sealing resin 8 has a resin front surface 81, a resin back surface82 and resin side surfaces 83. The resin front surface 81 and the resinback surface 82 face opposite to each other in the z direction. Theresin front surface 81 faces upward in FIGS. 3 and 5 , and the resinback surface 82 faces downward in FIGS. 3 and 5 . The resin sidesurfaces 83 connect the resin front surface 81 and the resin backsurface 82 and face either in the x direction or in the y direction.

In the present embodiment, the first-lead-terminal-portion end faces 123and the first-lead-connecting-portion end faces 133 of the first lead 1,the second-lead-terminal-portion end faces 223 and thesecond-lead-connecting-portion end face 233 of the second lead 2, thethird-lead-terminal-portion end faces 323 and thethird-lead-connecting-portion end face 333 of the third lead 3, thefourth-lead-terminal-portion end face 423 and thefourth-lead-connecting-portion end face 433 of the fourth lead 4, andthe fifth-lead-terminal-portion end face 523 and thefifth-lead-connecting-portion end face 533 of the fifth lead 5 are eachflush with one of the resin side surfaces 83 of the sealing resin 8. Inaddition, the mounting-portion back surface 112 and thefirst-lead-terminal-portion back surfaces 122 of the first lead 1, thewire-bonding-portion back surface 212 and thesecond-lead-terminal-portion back surfaces 222 of the second lead 2, thewire-bonding-portion back surface 312 and thethird-lead-terminal-portion back surfaces 322 of the third lead 3, thefourth-lead-terminal-portion back surface 422 of the fourth lead 4, andthe fifth-lead-terminal-portion back surface 522 of the fifth lead 5 areall flush with the resin back surface 82 of the sealing resin 8.

As shown in FIGS. 3 and 5 , the first-lead-terminal-portion end faces123, the second-lead-terminal-portion end faces 223, thethird-lead-terminal-portion end faces 323, thefourth-lead-terminal-portion end face 423 and thefifth-lead-terminal-portion end face 523 are all connected to the resinback surface 82 of the sealing resin 8. In contrast, as shown in FIG. 5, the first-lead-connecting-portion end faces 133, thesecond-lead-connecting-portion end face 233, thethird-lead-connecting-portion end face 333, thefourth-lead-connecting-portion end face 433 and thefifth-lead-connecting-portion end face 533 are all spaced apart from theresin back surface 82 of the sealing resin 8.

The following describes a method for manufacturing a semiconductordevice A1 with reference to FIGS. 8 and 9 . These figures are plan viewsin which the x direction, the y direction and the z direction correspondto those in FIG. 2 .

First, a lead frame 10 is prepared, as shown in FIG. 8 . The lead frame10 is a plate-like material from which the leads 1 to 5 will be formed.The lead frame 10 has a front surface 1010, which will form themounting-portion front surface 111, first-lead-terminal-portion frontsurfaces 121, first-lead-connecting-portion front surface 131,wire-bonding-portion front surface 211, second-lead-terminal-portionfront surfaces 221, second-lead-connecting-portion front surface 231,wire-bonding-portion front surface 311, third-lead-terminal-portionfront surfaces 321, third-lead-connecting-portion front surface 331,fourth-lead-terminal-portion front surface 421,fourth-lead-connecting-portion front surface 431,fifth-lead-terminal-portion front surface 521 andfifth-lead-connecting-portion front surface 531. The front surface 1010of the lead frame 10 is planar. In FIG. 8 , hatched regions with closelyspaced lines are where the thickness (z-direction dimension) is largerand correspond to the mounting portion 110, first-lead terminal portions120, wire bonding portion 210, second-lead terminal portions 220, wirebonding portion 310, third-lead terminal portions 320, fourth-leadterminal portion 420 and fifth-lead terminal portion 520. In contrast,hatched areas with widely spaced lines are where the thickness(z-direction dimension) is smaller and correspond to the first-leadconnecting portion 130, second-lead connecting portion 230, third-leadconnecting portion 330, fourth-lead connecting portion 430 andfifth-lead connecting portion 530. Those thinner regions are formed byhalf etching, for example. In the present embodiment, the base materialof the lead frame 10 contains Cu.

Next, as shown in FIG. 9 , the semiconductor elements 6 a and 6 b arebonded to the mounting portion 110 of the lead frame 10 with anelectrically conductive bonding material. Then, a bonding wire 71 isbonded to the first electrode 61 of the semiconductor element 6 a andthe fourth-lead terminal portion 420, and a plurality of bonding wires72 are bonded to the second electrode 62 of the semiconductor element 6a and the wire bonding portion 210 of the second lead 2. Similarly, abonding wire 71 is bonded to the first electrode 61 of the semiconductorelement 6 b and the fifth-lead terminal portion 520 of the fifth lead 5,and a plurality of bonding wires 72 are bonded to the second electrode62 of the semiconductor element 6 b and the wire bonding portion 310 ofthe third lead 3.

Then, the sealing resin 8 (not shown) is formed by curing a resinmaterial, so as to cover the semiconductor elements 6 a and 6 b, thebonding wires 71 and 72, and a portion of the lead frame 10. In thepresent embodiment, the sealing resin 8 is formed on the entire regionshown in FIG. 9 . Then, the lead frame 10 and the sealing resin 8 arecut along cut lines 85. This separates a chip that will be thesemiconductor device A1.

Next, the separated chip is processed to form a surface plating layer onthe leads 1 to 5 to cover their surfaces exposed from the sealing resin8. The surface plating layer may be deposited by immersing the chip in aplating solution to cause electroless displacement plating. As a result,a surface plating layer is deposited on the mounting-portion backsurface 112, first-lead-terminal-portion back surfaces 122,first-lead-terminal-portion end faces 123, first-lead-connecting-portionend faces 133, wire-bonding-portion back surface 212,second-lead-terminal-portion back surfaces 222,second-lead-terminal-portion end faces 223,second-lead-connecting-portion end face 233, wire-bonding-portion backsurface 312, third-lead-terminal-portion back surfaces 322.third-lead-terminal-portion end faces 323, third-lead-connecting-portionend face 333, fourth-lead-terminal-portion back surface 422,fourth-lead-terminal-portion end face 423,fourth-lead-connecting-portion end face 433, fifth-lead-terminal-portionback surface 522, fifth-lead-terminal-portion end face 523 andfifth-lead-connecting-portion end face 533. Note that the process ofelectroless displacement plating stops when base ions on the leads 1 to5 are replaced by ions in the solution to form a plating layer. That is,by electroless displacement plating, the surface plating layer cannot bedeposited to such a thickness that would significantly increase theheight of the surfaces of the leads 1 to 5. Therefore, although thesurface plating layer is added, the end faces of the leads 1 to 5 aremaintained flush with a resin side surface 83 and the back surfaces ofthe leads 1 to 5 are maintained flush with the resin back surface 82.

The semiconductor device A1 is obtained through the steps describedabove.

The following describes advantages of the semiconductor device A1.

In the present embodiment, the first lead 1 includes the mountingportion 110 on which the semiconductor elements 6 a and 6 b are mountedand the first-lead terminal portions 120 exposed from the sealing resin8 and serving as terminals. Each first-lead terminal portion 120includes a first-lead-terminal-portion end face 123 exposed from theresin side surface 83 and a first-lead-terminal-portion back surface 122exposed from the resin back surface 82. The first-lead-terminal-portionend face 123 and the first-lead-terminal-portion back surface 122 areconnected to form a terminal (see FIG. 6 ). To mount the semiconductordevice A1 on a circuit board, the terminals are soldered to circuitwiring on the circuit board. As a result of soldering, solder filletsform on the first-lead-terminal-portion end faces 123, indicating thatthe first-lead terminal portions 120 are joined to the circuit wiring.Thus, it is possible to visually confirm the bonding condition of thefirst lead 1 based on the post-mounting appearance of the product.

FIG. 10 is a perspective view illustrating the semiconductor device A1mounted on the circuit board 9. As shown, the semiconductor device A1 isplaced on the circuit board 9 and each terminal is soldered to circuitwiring 91 formed on the circuit board 9. With the semiconductor deviceA1, the first-lead terminal portions 120 are exposed from the sealingresin 8 and used as terminals, and they are joined to the circuit wiring91 by soldering. As a result, a solder fillet 92 forms between eachfirst-lead-terminal-portion end face 123 and the circuit wiring 91. Thepresence of solder fillets visually indicates that the first-leadterminal portions 120 are joined to the circuit wiring 91.

In the present embodiment, the first lead 1 has thefirst-lead-connecting-portion end faces 133 each of which is locatedbetween an end in the y direction and the first-lead-terminal-portionend face 123 nearest to that end as viewed in the z direction. Thefirst-lead-connecting-portion end faces 133 are cut surfaces formed in amanufacturing step of cutting connecting portions 1050 of the lead frame10 (see FIG. 9 ) along the cut lines 85. The connecting portions 1050increase the strength of the lead frame 10 for supporting a regioncorresponding to the first lead 1 to be formed, so that their edges inthe y direction are stably held during the process of bonding thesemiconductor elements 6 a and 6 b and bonding the bonding wires 71 and72 to the electrodes of the semiconductor elements 6 a and 6 b.

In the present embodiment, the first-lead-terminal-portion end faces 123are spaced apart from any first-lead-connecting-portion end face 133 inthe y direction. The y-direction dimension of the individual end face issmaller than it would be if all the end faces were provided as onecontinuous surface. This is effective to reduce the size of burrs in they direction, which may be formed in a manufacturing step of cutting thelead frame 10 in the y direction.

In the present embodiment, all the surfaces of the leads 1 to 5 exposedfrom the sealing resin 8 are provided with a surface plating layer. Thesurface plating layer is made of a material having better solderwettability than the base material of the leads 1 to 5. This facilitatesthe adhesion of solder to all the surfaces of the leads 1 to 5 exposedfrom the sealing resin 8 at the time of mounting the semiconductordevice A1 on, for example, a circuit board. Consequently, the bondingstrength of the semiconductor device A1 improves. In addition, a largersolder fillet 92 forms on each first-lead-terminal-portion end face 123.This makes it easier to confirm the bonding of the first lead 1 byinspecting the outer appearance after mounting.

Although in this embodiment, all the surfaces of the leads 1 to 5exposed from the sealing resin 8 are plated, the present disclosure isnot limited to such. The leads 1 to 5 may be without any surface platinglayer covering the surfaces exposed from the sealing resin 8. Althoughno surface plating layer is provided, small solder fillets 92 may stillform. Even if no solder fillet 92 forms, some amount of solder issqueezed out onto the circuit wiring 91. Thus, the bonding of the firstlead 1 can be confirmed by inspecting the outer appearance.

In the present embodiment, each of the first-lead-terminal-portion endfaces 123, first-lead-connecting-portion end faces 133,second-lead-terminal-portion end faces 223,second-lead-connecting-portion end face 233, third-lead-terminal-portionend faces 323, third-lead-connecting-portion end face 333,fourth-lead-terminal-portion end face 423,fourth-lead-connecting-portion end face 433, fifth-lead-terminal-portionend face 523 and fifth-lead-connecting-portion end face 533 is flushwith a resin side surface 83 of the sealing resin 8. However, thepresent disclosure is not limited to such. Each end face may beprojected beyond or retracted from a resin side surface 83. In addition,each end face may be flat, curved or corrugated. In addition, the outershape of each end face is not specifically limited.

In the present embodiment, each semiconductor element 6 has a backsurface electrode (third electrode 63), and the mounting-portion backsurface 112 serves as a back surface terminal, though the presentdisclosure is not limited to such a configuration. The semiconductorelement 6 may be without a back surface electrode, and themounting-portion back surface 112 then serves as a heat-dissipating padfor transferring head generated by the semiconductor element 6. Thebonding of the mounting-portion back surface 112 to the circuit board 9or a heat dissipating member can be confirmed by inspecting the outerappearance.

With reference to FIGS. 11 and 12 , a semiconductor device A2 accordingto a second embodiment will be described. In these figures, the same orsimilar elements to those of the semiconductor device A1 are denoted bythe same reference signs, and a redundant description thereof isomitted.

FIG. 11 is a perspective view of the semiconductor device A2. FIG. 12 isa right side view of the semiconductor device A2.

The semiconductor device A2 differs from the semiconductor device A1 inthe shape of the first lead 1. In the present embodiment, the first lead1 has four projections projecting in the x direction from the first-leadconnecting portion 130, and each projection is integral with afirst-lead terminal portion 120. That is, eachfirst-lead-terminal-portion end face 123 has a T-like shape, defined bya narrower portion 123 a and a wider portion 123 b that is wider thanthe narrower portion 123 a in the y direction. The narrower portion 123a is located toward the first-lead-terminal-portion back surface 122,and the wider portion 123 b is located toward thefirst-lead-terminal-portion front surface 121. In addition, the firstlead 1 does not have any first-lead-connecting-portion end face 133.Each first-lead-terminal-portion end face 123 of the semiconductordevice A2 may be considered as a combination of afirst-lead-terminal-portion end face 123 and afirst-lead-connecting-portion end face 133 according to the firstembodiment.

In the present embodiment, each first-lead terminal portion 120 includesa first-lead-terminal-portion end face 123 exposed from a resin sidesurface 83 and a first-lead-terminal-portion back surface 122 exposedfrom the resin back surface 82, and the first-lead-terminal-portion endface 123 and the first-lead-terminal-portion back surface 122 connectedto form a terminal. When the semiconductor device A2 is joined to acircuit board, a solder fillet forms on each first-lead-terminal-portionend face 123. This enables the bonding of the first lead 1 to beconfirmed by inspecting the outer appearance.

In the present embodiment, in addition, the first lead 1 has nofirst-lead-connecting-portion end face 133. The spacing between thewider portion 123 b of each first-lead-terminal-portion end face 123 andthe second-lead-connecting-portion end face 233 (or thethird-lead-connecting-portion end face 333) in the y direction isgreater than the spacing according to the first embodiment between eachfirst-lead-connecting-portion end face 133 and thesecond-lead-connecting-portion end face 233 (or thethird-lead-connecting-portion end face 333). This reduces thepossibility that burrs are formed on the first-lead-terminal-portion endfaces 123 in the cutting step and accidentally connected to thesecond-lead-connecting-portion end face 233 (or thethird-lead-connecting-portion end face 333).

In the present embodiment, each first-lead-terminal-portion end face 123has a wider portion 123 b that is wider than the narrower portion 123 ain the y direction. The lead frame 10 (see FIG. 9 ) used in themanufacturing steps has portions which will form the wider portions 123b of the first-lead terminal portions 120. These portions increase thestrength of the lead frame 10 for supporting a region corresponding tothe first lead 1 to be formed, so that their edges in the y directionare stably held during the process of bonding the semiconductor elements6 a and 6 b and bonding the bonding wires 71 and 72 to the electrodes ofthe semiconductor elements 6 a and 6 b.

With reference to FIG. 13 , a semiconductor device A3 according to athird embodiment will be described. In FIG. 13 , the same or similarelements to those of the semiconductor device A1 are denoted by the samereference signs, and a redundant description thereof is omitted. FIG. 13is a bottom view of the semiconductor device A3.

The semiconductor device A3 differs from the semiconductor device A1 inthe shape of the first lead 1. The first lead 1 of the presentembodiment is configured such that the first-lead connecting portion 130surrounds the mounting portion 110, and the first-lead terminal portions120 are provided on either end face of the first-lead connecting portion130 in the x direction. The first lead 1 of the present embodiment maybe considered similar to the first lead 1 of the first embodiment,except that each first-lead-terminal-portion back surface 122 is notconnected to the mounting-portion back surface 112. In the presentembodiment, although the mounting-portion back surface 112 and thefirst-lead-terminal-portion back surfaces 122 are not connected, themounting portion 110 and the first-lead terminal portions 120 areconnected via the first-lead connecting portions 130.

The present embodiment achieves the same advantages as those achieved bythe first embodiment.

With reference to FIG. 14 , a semiconductor device A4 according to afourth embodiment will be described. In FIG. 14 , the same or similarelements to those of the semiconductor device A1 are denoted by the samereference signs, and a redundant description thereof is omitted. FIG. 14is a bottom view of the semiconductor device A4.

The semiconductor device A4 differs from the semiconductor device A1 inthe shape of the first lead 1. The first lead 1 according to the presentembodiment has one first-lead terminal portion 120 on either end face ofthe mounting portion 110 in the x direction and at a center of the endface in the y direction. That is, two first-lead terminal portions 120are provided in total.

The present embodiment achieves the same advantages as those achieved bythe first embodiment.

With reference to FIG. 15 , a semiconductor device A5 according to afifth embodiment will be described. In FIG. 15 , the same or similarelements to those of the semiconductor device A1 are denoted by the samereference signs, and a redundant description thereof is omitted. FIG. 15is a bottom view of the semiconductor device A5.

The semiconductor device A5 differs from the semiconductor device A1 inthe shape of the first lead 1. The first lead 1 according to the presentembodiment has one first-lead terminal portion 120 on one end face ofthe mounting portion 110 in the x direction and at a center of the endface in the y direction. That is, only one first-lead terminal portion120 is provided in total.

The present embodiment achieves the same advantages as those achieved bythe first embodiment.

As shown in the first, fourth and fifth embodiments, the number of thefirst-lead terminal portions 120 included in the first lead 1 is notlimited. It is sufficient that the first lead 1 includes at least onefirst-lead terminal portion 120. As long as the first lead 1 includes atleast one first-lead terminal portion 120, the bonding of the first lead1 can confirmed by inspecting the appearance.

With reference to FIG. 16 , a semiconductor device A6 according to asixth embodiment will be described. In FIG. 16 , the same or similarelements to those of the semiconductor device A1 are denoted by the samereference signs, and a redundant description thereof is omitted. FIG. 16is a bottom view of the semiconductor device A6.

The semiconductor device A6 differs from the semiconductor device A1 inthe shapes of the first lead 1, the second lead 2 and the third lead 3.The second lead 2 according to the present embodiment only has twosecond-lead terminal portions 220, and the wire bonding portion 210 issmaller in the x-direction dimension than that in the first embodiment.The x-direction dimension of the second lead 2 is accordingly smaller,and the spacing between the second lead 2 and the fourth lead 4 iswider. In addition, the third lead 3 according to the present embodimentonly has two third-lead terminal portions 320, and the wire bondingportion 310 is smaller in the x-direction dimension than that in thefirst embodiment. The x-direction dimension of the third lead 3 isaccordingly smaller, and the spacing between the third lead 3 and thefifth lead 5 is wider.

The first lead 1 according to the present embodiment has two first-leadterminal portions 120. One of the first-lead terminal portions 120 isconnected to one end face of the mounting portion 110 in the y directionand located between the second lead 2 and the fourth lead 4. The otherof the first-lead terminal portions 120 is connected to the other endface of the mounting portion 110 in the y direction and located betweenthe third lead 3 and the fifth lead 5. That is, eachfirst-lead-terminal-portion end face 123 faces in the y direction.

Also in the present embodiment, each first-lead terminal portion 120serves as a terminal where the first-lead-terminal-portion end face 123exposed from a resin side surface 83 and the first-lead-terminal-portionback surface 122 exposed from the resin back surface 82 are connected toeach other. When the semiconductor device A6 is joined to a circuitboard, a solder fillet forms on each first-lead-terminal-portion endface 123. This enables visual confirmation of the bonding of the firstlead 1, merely by inspecting the post-mounting appearance of theproduct.

Also in the present embodiment, the lead frame 10 (see FIG. 9 ) used inthe manufacturing steps has connecting portions 1050. The first lead 1of this embodiment includes a first-lead terminal portion 120 on eitherend face of the mounting portion 110 in the y direction. Thisconfiguration increases the strength of the lead frame 10 for supportinga region corresponding to the mounting portion 110 to be formed, so thattheir edges in the y direction are stably held during the process ofbonding the semiconductor elements 6 a and 6 b and bonding the bondingwires 71 and 72 to the electrodes of the semiconductor elements 6 a and6 b.

With reference to FIG. 17 , a semiconductor device A7 according to aseventh embodiment will be described. In FIG. 17 , the same or similarelements to those of the semiconductor device A1 are denoted by the samereference signs, and a redundant description thereof is omitted. FIG. 17is a bottom view of the semiconductor device A7.

The semiconductor device A7 differs from the semiconductor device A1 inthe shape of the first lead 1 and also differs in that a sixth lead 600and a seventh lead 700 are additionally included. As compared with firstembodiment, the mounting portion 110 of the first lead 1 is smaller inthe x-direction dimension, and each first-lead terminal portion 120 ofthe first lead 1 is larger in the x-direction. The sixth lead 600 islocated between the two first-lead terminal portions 120 on one end faceof the mounting portion 110 in the x direction, and the seventh lead 700is located between the two first-lead terminal portions 120 on the otherend face of the mounting portion 110 in the x direction. Both the sixthlead 600 and the seventh lead 700 are separated from the first lead 1.

The sixth lead 600 includes a sixth-lead terminal portion 620. Thesixth-lead terminal portion 620 is rectangular as viewed in z direction.The sixth-lead terminal portion 620 has a sixth-lead-terminal-portionfront surface 621, a sixth-lead-terminal-portion back surface 622 and asixth-lead-terminal-portion end face 623. Thesixth-lead-terminal-portion front surface 621 and thesixth-lead-terminal-portion back surface 622 face opposite to each otherin the z direction. The sixth-lead-terminal-portion front surface 621 iswhere a bonding wire is bonded. The sixth-lead-terminal-portion end face623 faces outward in the x direction and connects thesixth-lead-terminal-portion front surface 621 and thesixth-lead-terminal-portion back surface 622. Thesixth-lead-terminal-portion back surface 622 and thesixth-lead-terminal-portion end face 623 are exposed from the sealingresin 8 and connected to form a terminal. The sixth lead 600 has asurface plating layer (not shown) on all the surfaces exposed from thesealing resin 8. In the present embodiment, the surface plating layer isprovided on the sixth-lead-terminal-portion back surface 622 and thesixth-lead-connecting-portion end face 623.

The seventh lead 700 includes a seventh-lead terminal portion 720. Theseventh-lead terminal portion 720 is rectangular as viewed in zdirection. The seventh-lead terminal portion 720 has aseventh-lead-terminal-portion front surface 721, aseventh-lead-terminal-portion back surface 722 and aseventh-lead-terminal-portion end face 723. Theseventh-lead-terminal-portion front surface 721 and theseventh-lead-terminal-portion back surface 722 face opposite to eachother in the z direction. The seventh-lead-terminal-portion frontsurface 721 is where a bonding wire is bonded. Theseventh-lead-terminal-portion end face 723 faces outward in the xdirection and connects the seventh-lead-terminal-portion front surface721 and the seventh-lead-terminal-portion back surface 722. Theseventh-lead-terminal-portion back surface 722 and theseven-lead-terminal-portion end face 723 are exposed from the sealingresin 8 and connected to form a terminal. The seventh lead 700 has asurface plating layer (not shown) on all the surfaces exposed from thesealing resin 8. In the present embodiment, the surface plating layer isprovided on the seventh-lead-terminal-portion back surface 722 and theseventh-lead-connecting-portion end face 723.

The present embodiment achieves the same advantages as those achieved bythe first embodiment. The present embodiment may include an additionalsixth-lead terminal portion 620 and an additional seventh-lead terminalportion 720 each of which is exposed from a resin side surface 83 of thesealing resin 8 facing in the x direction. However, the semiconductordevice A7 may be without one of the sixth lead 600 and the seventh lead700.

The sixth lead 600 and the seventh lead 700 may added to thesemiconductor device A6 shown in FIG. 16 . Specifically, for thesemiconductor device A6, the sixth lead 600 can be disposed between twoprojected portions on one end face of the first-lead connecting portion130 in the x direction, and the seventh lead 700 can be disposed betweenthe two projected portions on the other end face of the first-leadconnecting portion 130 in the x direction. Both the sixth lead 600 andthe seventh lead 700 may be separated from the first lead 1.

With reference to FIG. 18 , a semiconductor device A8 according to aneighth embodiment will be described. In FIG. 18 , the same or similarelements to those of the semiconductor device A1 are denoted by the samereference signs, and a redundant description thereof is omitted. FIG. 18is a perspective view of the semiconductor device A8.

The semiconductor device A8 differs from the semiconductor device A1 inthe shape of each first-lead terminal portion 120. Each first-leadterminal portion 120 of the present embodiment is in a wedge shapetapering toward the outer end. While the first-lead-terminal-portionback surface 122 is connected to a resin side surface 83, the first-leadterminal portion 120 is not exposed from the resin side surface 83 andno first-lead-terminal-portion end face 123 is present.

In the present embodiment, each first-lead-terminal-portion back surface122 is connected to the resin side surface 83, so that solder issqueezed out onto the circuit wiring 91 when the semiconductor device A8is attached to the circuit board 9. This the enables the bonding of thefirst lead 1 to be confirmed by inspecting the outer appearance.

The semiconductor devices according to the semiconductor devices are notlimited to the specific embodiments described above. Various designchanges may be made to the specific structure of each portion of thesemiconductor devices according to the present disclosure.

The invention claimed is:
 1. A semiconductor device comprising: asemiconductor element; a first lead including a mounting portion onwhich the semiconductor element is mounted, a first terminal portionconnected to the mounting portion and a second terminal portionconnected to the mounting portion; a second lead spaced apart from thefirst lead and formed with a plurality of terminal portions; a thirdlead spaced apart from the first lead and the second lead and formedwith at least one terminal portion; and a sealing resin covering thesemiconductor element, a portion of the first lead, a portion of thesecond lead and a portion of the third lead, wherein the mountingportion includes a mounting-portion front surface and a mounting-portionback surface that are opposite to each other in a thickness direction,the semiconductor element being mounted on the mounting-portion frontsurface, the sealing resin includes a resin front surface, a resin backsurface, a resin first side surface and a resin second side surface, theresin front surface and the resin back surface being opposite to eachother in the thickness direction, each of the resin first side surfaceand the resin second side surface connecting the resin front surface andthe resin back surface, the resin first side surface having two mutuallyseparated edges each extending in the thickness direction, themounting-portion back surface is flush with the resin back surface, thefirst terminal portion includes a first-terminal-portion back surfaceexposed from the resin back surface and extending to the resin firstside surface, the first-terminal-portion back surface being flush withthe mounting-portion back surface, the second terminal portion incudes asecond-terminal-portion back surface exposed from the resin back surfaceand extending to the resin first side surface, thesecond-terminal-portion back surface being flush with themounting-portion back surface, the first terminal portion includes afirst-terminal-portion end face exposed from the resin first sidesurface in a manner such that the first-terminal-portion end face as awhole is spaced apart from the two edges of the resin first sidesurface, the first-terminal-portion end face being connected to thefirst-terminal-portion back surface, the second terminal portion incudesa second-terminal-portion end face exposed from the resin first sidesurface in a manner such that the second-terminal-portion end face as awhole is spaced apart from the two edges of the resin first sidesurface, the second-terminal-portion end face being connected to thesecond-terminal-portion back surface, the first-terminal-portion endface and the second-terminal-portion end face are arranged symmetricalwith a center line of the resin first side surface that is parallel tothe thickness direction, the plurality of terminal portions of thesecond lead and the at least one terminal portion of the third lead areexposed from the resin second side surface.
 2. The semiconductor deviceaccording to claim 1, further comprising wires each extending from thesemiconductor element to the second lead.
 3. The semiconductor deviceaccording to claim 2, further comprising a single additional wireextending from the semiconductor element to the third lead.
 4. Thesemiconductor device according to claim 3, further comprising anadditional semiconductor element mounted on the mounting-portion frontsurface.
 5. The semiconductor device according to claim 1, wherein thefirst lead includes a connecting-portion end face that is exposed fromthe resin first side surface and spaced apart from the resin backsurface.
 6. The semiconductor device according to claim 1, wherein thefirst-terminal-portion end face includes a narrower portion and a widerportion, the narrower portion is located closer to thefirst-terminal-portion back surface than is the wider portion, and thewider portion has a greater dimension than the narrower portion in adirection perpendicular to the thickness direction.
 7. The semiconductordevice according to claim 1, wherein the first-terminal-portion backsurface and the mounting-portion back surface are connected to eachother.
 8. The semiconductor device according to claim 1, wherein each ofthe first terminal portion and the second terminal portion includes anadditional part that is exposed from the resin first side surface otherthan the first-terminal-portion end face and the second-terminal-portionend face.
 9. The semiconductor device according to claim 1, wherein thesealing resin includes a resin third side surface opposite to the resinfirst side surface, the first lead is formed with a third terminalportion exposed from the resin third side surface.
 10. The semiconductordevice according to claim 1, further comprising a fourth lead (2 or 4)that is opposite to the second lead or the third lead with respect tothe first lead as viewed in the thickness direction.
 11. Thesemiconductor device according to claim 10, wherein the sealing resinincludes a resin fourth side surface opposite to the resin second sidesurface, the fourth lead is formed with at least one terminal portionexposed from the resin fourth side surface.
 12. The semiconductor deviceaccording to claim 11, further comprising a fifth lead that is oppositeto the second lead or the third lead with respect to the first lead asviewed in the thickness direction, the fifth lead being spaced apartfrom the fourth lead, the fifth lead is formed with at least oneterminal portion exposed from the resin fourth side surface.
 13. Thesemiconductor device according to claim 12, wherein each of the fourthlead and the fifth lead is exposed from the the resin back surface. 14.The semiconductor device according to claim 12, wherein the fourth leadincludes a part that is exposed from the resin first side surface, andthe fifth lead includes a part that is exposed from the resin third sidesurface.
 15. The semiconductor device according to claim 1, wherein thefirst lead is electrically connected to the semiconductor element. 16.The semiconductor device according to claim 15, wherein thesemiconductor element includes an electrode formed on a surface facingthe first lead.
 17. The semiconductor device according to claim 1,wherein the semiconductor element comprises a transistor.
 18. Thesemiconductor device according to claim 1, wherein the first lead isformed with a surface plating layer on a portion exposed from thesealing resin.